This section provides background information related to the present disclosure which is not necessarily prior art.
Heat exchangers are used in automotive vehicles to heat or cool various components of the vehicle. Heat exchangers typically include a pair of fluid tanks, a plurality of tubes, a plurality of fins and a pair of support members. Each of the plurality of tubes extends between the pair of fluid tanks and each of the plurality of tubes defines one or more fluid passages that are in direct communication with a tank cavity defined by each of the fluid tanks. Each of the plurality of fins is disposed between adjacent tubes to increase the heat transfer area of the heat exchanger. The pair of support members are located on opposite sides of the stacked tubes and fins to provide support for the heat exchanger. Heat is transferred between a fluid flowing in the passages of the tubes between the fluid tanks and a fluid flowing over the tubes and fins.
The tank bodies that form the fluid tanks can be made from a variety of materials including metals and plastics. The specific material depends on the strength and/or temperature requirements for the heat exchanger. Plastic tank bodies have been utilized when the requirements permit and these plastic tank bodies reduce weight and costs while still providing the necessary strength and durability. In order to increase the stiffness of the plastic tank body, grooves are added to the molded plastic tank body. When the tank body has a uniform cross-section along its length, these grooves increase the stiffness without reducing the strength of the plastic tank body.
Some plastic tank bodies are designed with a crown surface which is at an angle with the longitudinal length of the plastic tank body. The crown surface is typically used to locate a fluid inlet for adding additional fluid to the heat exchanger. When a vertical groove is formed in the crown surface of the plastic tank body, the wall thickness of the plastic tank body is reduced at one side of the groove and the wall thickness is increased at the opposite side of the groove due to the intersection of the groove with the crown surface. The reduced wall thickness weakens the plastic tank body. In addition, the increased wall thickness could create molding voids due to the larger volume which needs to be filled with plastic during the molding process.